I. Purpose

The Albert Einstein College of Medicine is committed to protecting its employees, students and the environment from the hazards associated with its activities. This Tuberculosis Control Program (TCP) is another indication of this commitment. The TCP is designed to provide employees and students with information, guidelines and policy designed to prevent exposure to the tuberculosis bacteria. Where there is a lack of information or specific regulation in areas of this program we will offer the best available advice.

II. Scope

III. Introduction

Tuberculosis is an infectious disease of the lungs and other organs caused by the bacterium Mycobacterium tuberculosis. The disease has long been and still is a major cause of disability and premature death throughout most of the world.

M. tuberculosis is carried in airborne particles, known as droplet nuclei, that can be generated when persons with pulmonary or laryngeal tuberculosis sneeze, cough, speak or sing. The particles are so small (1-5 microns) that normal air currents keep them airborne and can spread them throughout a room or building. Infection occurs when a susceptible person inhales droplet nuclei containing M. tuberculosis, and bacilli become established in the alveoli of the lungs. Two to ten weeks after initial human infection with M. tuberculosis, the immune response usually limits further multiplication and spread of the tuberculosis bacilli. For a small proportion of newly infected persons (usually <1%), initial infection rapidly progresses to clinical illness. However, for another group (approximately 5%-10%), illness develops after an interval of months, years or decades, when the bacteria begin to replicate and produce disease. The risk of progression to active disease is markedly increased for persons with HIV infection, and other individuals with weakened resistance to illness or disease.

A distinction must be made between an individual who has been exposed to the tubercle bacillus and demonstrates a positive PPD screening test but has no signs of active disease, and the individual who is PPD positive with active disease. The former is not considered infectious unless symptoms develop, while the latter is considered infectious.

The probability that a susceptible person will become infected depends upon the concentration of infectious droplet nuclei in the air and a number of patient, environmental, and work practices influencing transmission of the disease.

Patient Factors that Enhance Transmission Include:

delayed diagnosis of tuberculosis

anatomic site of disease

presence of cough

presence of bacterium in sputum smear

forgetting to cough into a tissue

presence of cavitation on chest x-ray

length of time the patient has been on adequate chemotherapy

duration of symptoms

administration of procedures that can enhance coughing (e.g., sputum induction).

Environmental Factors that Enhance Transmission Include:

contact between susceptible persons and an infectious patient in relatively small, enclosed spaces

inadequate ventilation that results in insufficient dilution or removal of infectious droplet nuclei, and

recirculation of air containing infectious droplet nuclei.

Work Practices that Enhance Transmission Include:

lack of education and training concerning tuberculosis

lack of personal protective equipment (e.g., respirators not being used)

no tuberculosis screening and medical surveillance of workers at-risk.

The hazards associated with tuberculosis infection have increased with the development of multiple drug resistant strains of tuberculosis (MDRTB). There are many strains of MDRTB present in the population today, with many of these being resistant to up to six (6) of the standard antibiotics normally used to treat the disease. With the delay of effective drug therapy, patients remain in an infectious state for longer periods of time, thereby increasing the risk of infection to those around them. Cases of tuberculosis contracted in an occupational setting have been reported, and it is anticipated that the likelihood of fatalities from occupationally acquired tuberculosis will increase.

IV. At-Risk Individuals

Immunosuppression, homelessness, overcrowding, malnutrition and lack of medical care are the most common factors increasing the risk to individuals for contracting tuberculosis. Groups known to have a higher incidence of tuberculosis include current or past prison inmates, alcoholics, intravenous (IV) drug users, the elderly, foreign-born persons from areas of the world with a high prevalence of tuberculosis (e.g., Asia, Africa, the Caribbean, and Latin America), and persons living in the same household as members of these groups.

Healthcare workers should be particularly alert to the need for preventing tuberculosis transmission in healthcare settings in which persons with HIV infections receive care, especially if cough-inducing procedures such as sputum induction and aerosolized pentamidine treatments are being performed.

Aside from the risks associated with medical care or evaluation that may be given at the above facilities, the major concerns at these institutions with respect to tuberculosis transmission are crowding and provisions for adequate ventilation. This is especially important if individuals at these facilities are free to move around the facility with active undiagnosed cases of tuberculosis.

ResearchIn research, transmission risk is increased by procedures which result in aerosolization of bacterium containing preparations. Examples of such procedures are:

pipetting

vortexing

centrifugation

homogenization

inoculation.

In research, transmission of M. tuberculosis can also result from the contamination of working surfaces and personnel by viable bacterium.

VI. Determination of Risk of Exposure to TB

New York State Department of Health (NYSDOH) regulation specifies that all staff working in health care programs licensed by NYSDOH are considered at risk for TB. This includes employees and students who work at Jacobi Hospital and other affiliated hospitals, Children's Evaluation and Rehabilitation Center (CERC), Substance Abuse, and Soundview/Throgs Neck Mental Health Center (SVTN). Employees and students working in other clinical areas that are not licensed are also considered at risk, as are those working in selected research areas.

Your immediate Supervisor, Administrator, Departmental Chairperson, Employee Health Service or the Department of Environmental Health & Safety will evaluate whether or not you are at risk for exposure to tuberculosis while at work. A Health and Safety Assessment form should be completed for each employee, noting risk of TB exposure. The assessment form will be returned to Human Resources with a copy sent to EH&S. The appropriate follow up will be made.

VII. Mechanisms and Routes of Transmission

The most common route of exposure to tubercle bacilli is the inhalation of tubercle bacilli in droplet nuclei. The importance of spread by direct contact, sexual or otherwise, or by ingestion of organisms other than infected dairy products is undetermined and considered slight. Tuberculin testing of dairy cattle and pasteurization of milk have virtually eliminated bovine tuberculosis in the United States and the possibility of spreading through diary products.

When an individual with tubercle bacilli in his sputum coughs, sneezes, talks or sings, a spray of secretion may be expelled. Talking and singing are more important in the transmission of laryngeal tuberculosis. Droplet nuclei of tubercle bacilli form when exposed to air. These droplet nuclei float with the air currents for a long time and for long distances. When inhaled, the droplet nuclei pass directly to the alveoli of the lung causing infection.

VIII. Symptoms of Exposure

Tuberculosis can be both symptomatic and non-symptomatic. With all forms of the disease, there may be symptoms of chronic infection, loss of appetite, nightsweats, weight loss, fatigue, and low-grade fever. Many individuals have latent, unapparent old infections.

Pulmonary tuberculosis is the most common form of the disease, accounting for 83% of the cases reported in the United States in 1985. The most common symptom is a chronic cough, usually productive of mucoid or mucopurulent sputum. A dull aching in the chest is sometimes reported. Occasionally, tuberculosis can present as an acute respiratory illness with symptoms resembling those of influenza or pneumonia.

Miliary tuberculosis is generally not infectious through the airborne route, if it has not spread to the lungs. It is more likely to be transmitted via surface contact. Symptoms ofthis illness include fever and multiple lesions in many organs of the body. Tuberculosis meningitis, which often accompanies miliary tuberculosis, can result in symptoms such as headache, abnormal behavior, clouded consciousness or convulsions.

There are a number of other types of tuberculosis disease including lymph node, pleural and bone and joint disease. Tuberculosis can spread throughout the body and involve many organs and systems of the body.

The appropriate health service (Weiler or Student Health) or your physician are best able to determine if you have been infected.

IX. How To Protect Yourself From Exposure To Tubercle Bacillus

History indicates that a decline in tuberculosis was present in many countries even before the discovery of the tubercle bacillus. This decline in illness is attributed to improved ventilation and natural daylight in homes and places of employment, decreased working hours and improved nutrition. Improvements along these lines continued up until the early 1980's when increasing poverty with associated conditions of unaddressed illness led to an increase in tuberculosis. The recent development of drug resistant strains of the bacillus has further increased the spread of this disease. In addition to the above factors of adequate ventilation, improved daylight, decreased working hours and improved nutrition, factors such as isolation, personal protective equipment and worker training contribute greatly to protection from exposure.

Isolation of the Patient

Patients must be isolated if they are in an active phase of their illness and are infectious. The isolation is designed to prevent airborne spread of the bacillus. Patients should be taught to cover their mouth and nose with disposable tissues when coughing or sneezing. There should be ventilation in the room without recirculation of air; preferably, the air should be exhausted directly to the outside. There may be a requirement for use of respirators when examining or visiting these patients (see section on respirator recommendations).

Adequate Ventilation

In simple terms, ventilation in buildings, rooms, etc., involves supply air, exhaust air, and air treatment (heating or cooling). The amount of air supplied and exhausted and the dimensions of the room determine the number of air changes per hour. Increasing the number of air changes in a room reduces the buildup of potentially harmful agents in the breathing zone.

Research procedures which may generate hazardous aerosols such as pipetting, centrifugation, pouring, or mixing, must be performed in a biosafety cabinet or a fume hood. These are isolated ventilation systems which do not reintroduce harmful agents back into the breathing zone.

Since tuberculosis can be transmitted from person to person by an infectious aerosol, ventilation must be sufficient to prevent the buildup of infectious particles. Areas of high risk such as healthcare settings or clinic settings should anticipate potential exposure and have at least 6 air changes per hour; preferably each change vented to the outside with no recirculation of air. Research laboratories using a variety of hazardous materials typically employ 10 air changes per hour. There are portable air filtration units which can be installed in high risk areas which can assist in the reduction of infectious aerosols. These units have HEPA filters which can filter out infectious particles. The effectiveness of these units is currently being studied.

Ultraviolet Light

Experimental results indicate that ultraviolet light (UV) can destroy tubercle bacillus. UV treatment has been recommended for inactivating infectious tubercle bacillus in the air of certain high risk rooms. The UV treatment is usually accomplished by the placement of a series of UV lamps along the perimeter of the ceiling of the room. UV light then treats the air as it is supplied or exhausted. There is considerable controversy regarding the use of UV for treating air to remove infectious agents. Factors such as safety (UV injury to the eye) and the efficiency and effectiveness of the UV light to inactivate infectious particles in the air are all part of the controversy. It may be appropriate to use a combination of HEPA air filtration and UV light treatment of air for certain high risk procedures such as sputum induction procedures and administering aerosolized pentamadine to AIDS patients. (Note that AIDS patients must be tested for sputum TB infectivity or smear positivity before aerosolized pentamadine therapy.) The appropriateness of these solutions must be made on the best available information and the conditions present.

Personal Protective Equipment

Since transmission of the tubercle bacilli is most common via inhalation of aerosolized infectious droplets, the respirator becomes the primary piece of PPE which must be considered. Respirators are of two general types - air filtration and air supply. Air filtration respirators, as the name implies, filter air that reaches the breathing zone of the worker. A number of air filtration respirators have been recommended for use in the prevention of TB transmission by the Occupational Health and Safety Administration (OSHA).

Three examples of approved TB respirators are given in Appendix A. They are the Tecnol PFR95 Particulate Filter Respirator, the 3M 1860/1860S Health Care N95 Particulate Respirator, and the 3M 8233 N100 Particulate Respirator. All respirators require medical screening and a Fit

Test before use. The 3M 1860/1860S N95 Particularte Respirator is inexpensive and comfortable to use. Another type of air filtration respirator is the Powered Air Purifying Respirator (PAPR). This respirator contains a pump which forces air through a HEPA filter and into the breathing zone of the worker. This respirator does not rely on the user to draw air through a filter. It is less taxing and more efficient than simple air filtration through a filter, however it is more bulky for the user to wear. Another category of respirator is the air supply respirator which is generally considered to provide the most protection to a worker exposed to airborne hazards. The reason for this is that air is supplied by tank or pump from an uncontaminated source. Thus, the user is always assured of uncontaminated air. OSHA has not adopted the PAPR Respirator or the Air Supply Respirator for TB Control.

There has recently been some controversy in the use of or appropriateness of respirators to protect against tuberculosis exposure. Respirators have been recommended to provide 100% protection from tubercle bacillus, but it is not clear whether this level of protection is necessary when you consider the fact that healthcare professionals can routinely be in contact with tuberculosis patients without becoming infected themselves. Regulations may change over time with respect to the use of respirators for tuberculosis protection, reflecting more careful studies of the transmissibility of the tubercle bacillus in air. Additionally, exposure may occur when TB is not yet diagnosed or not expected.

There are advantages and short comings of all respirators, but the important thing to remember is that they are designed for user protection. With proper training and repeated use, individuals can become more comfortable with them.

Guidelines for Using Respirators to Prevent TB Transmission

If an individual must wear a respirator during the course of their work, they must be part of Albert Einstein College of Medicine's Institutional Respiratory Protection Program (RPP). The RPP includes medical evaluation, respirator selection, training, and a fit-test. A summary of Albert Einstein College of Medicine's RPP can be found in Appendix B.

For laboratory research involving the tubercle bacillus, respirators are generally not required since any work involving potentially infectious aerosols must be performed in a certified biosafety cabinet in our biohazard facility. Many laboratory workers using infectious agents use face masks (surgical mask) when working. These masks are not a substitute for a National Institute of Occupational Safety and Health (NIOSH) approved respirator.

Masks, as distinguished from an approved respirator, do not form a perfect seal on the face and do not have the appropriate filtration to keep infectious particles in air from the breathing zone. Face masks do serve an important function of keeping the hands away from the mouth, nose and eyes. If there is a spill of infectious material in the laboratory, then anyone performing the cleanup must wear an approved, properly fitted respirator. Where necessary, Tecnol PFR95 Particulate Filter Respirator, the 3M 1860/1860S Health Care N95 Particulate Respirator, 3M 8233 N100 Particulate Respirator or other comparable respirators are supplied in the laboratory. Additional respirators can be obtained through the Laboratory Safety Officer or Industrial Hygienist at X3560.

In hospitals and other clinical settings the following policies have been adopted.

a. Employees or students entering rooms or otherwise having contact with patients with infectious TB will wear a properly fitted Dust/Mist/Fume High-Efficiency Particulate Respirator capable of filtering small (1-5 micron) particles or an approved Particulate Respirator. (The Tecnol PFR95 Particulate Filter Respirator, the 3M 1860/1860S Health Care N95 Particulate Respirator and the 3M 8233 N100 Particulate Respirator are currently approved for this purpose. Other respirators may also be approved. Check with NIOSH.)

b. The appropriate Dust/Mist/Fume High Efficiency Particulate Respirator, or approved Particulate Respirator, properly fitted, will be used for those having contact with patients with confirmed or suspected infectious TB in special procedure areas: (The Tecnol PFR95 Particulate Filter Respirator, the 3M 8233 N100 Particulate Respirator and the 3M 1860/1860S Health Care N95Particulate Respirator, or the are currently approved for this purpose. Other respirators may also be approved. Check with NIOSH.)

e. If individuals are required to wear a respirator during the course of their work, (see page 5) then they must be a part of the Albert Einstein College of Medicine's Respiratory Protection Program (RPP) for TB Exposure. This program will be coordinated by the Department of Environmental Health and Safety in conjunction with the appropriate Employee or Student Health Service. The RPP includes medical evaluation, selection, training and fit testing for all workers who must wear respirators.

f. All employees whose jobs require them to use a respirator will be assessed medically by the appropriate Employee or Student Health Service or a comparable medical contractor for any medical contraindications for respirator use (e.g., pulmonary disease). Any medical problems which are encountered from the use of personal protective devices will be reported to and evaluated by the appropriate Employee or Student Health Service.

g. Employees and students who pass the medical assessment will be trained in the proper selection, care, use, storage and disposal of particulate respirators. The training will include fit testing using the Bitrex solution. Cases in which an adequate fit cannot be obtained with the designated device will be handled on an individual basis. The training will be conducted by the respirator manufacturer, the Department of Environmental Health and Safety, or as otherwise designated by the institution in which the employee or student works.

X. Immunizations

Immunization against tuberculosis is currently limited to the use of the Bacillus Calmette - Guerin vaccine (BCG), an attenuated organism, developed from subcultures of Mycobacterium bovis. BCG has been studied extensively with respect to its usefulness in preventing illness. Despite this, there is disagreement about its effectiveness. Characteristics of BCG vaccines can change with continued cultivation leading to the variable effectiveness of the vaccine. In light of the above, Albert Einstein College of Medicine has adopted the following policy regarding BCG vaccination of employees and students:

If a good PPD screening program, combined with an effective INH chemotherapy prophylaxis and a good infection control program is in place, BCG should not be provided. This is because PPD/INH/infection control is more consistently effective than the present BCG vaccine and the latter can interfere with the efficacy of the former.

BCG should only be used for health care workers in environments where PPD screening and INH chemotherapy programs cannot be used.

At this time because there are good PPD screening programs, BCG vaccination will not be recommended. For further information regarding BCG vaccination, please visit the Employee or Student Health Service or your personal physician.

XI. Screening and Evaluation for T.B. Exposure

This policy applies to all students as well as to all employees who work in hospitals, other health care settings, or research laboratories that handle the tubercle bacillus. The services that follow will be provided through Albert Einstein College of Medicines Occupational Health Service. Compliance with the tuberculin screening policy is mandatory for students and is a condition of continued employment for those working in the settings identified above. Those working in programs licensed by the NYSDOH must be screened before starting to work.

A. Standard Tuberculin Skin Test Screening

Screening for tuberculosis exposure involves the administration of the PPD test. If the PPD test is positive, then a physical evaluation by a physician must be made to include an examination for signs and symptoms and, if necessary, bacteriological

examination of sputum and chest x-ray. Immunosuppressed individuals who are exposed to tuberculosis may have acquired primary tuberculosis infection. Such individuals may not respond to tuberculin testing and therefore should be assessed by a symptom check, chest X-ray or physical examination. Anergy screens which are used to determine the competency of cell mediated immunity, remain controversial in this setting.

The standard tuberculin test is administered by the Mantoux technique, whereby 0.1 ml. of the test material is injected under the skin of the forearm by needle and syringe. The test material is a purified protein derivative of old tuberculin (PPD or RT), which should come from a large, well standardized batch of tuberculin and be protected against absorption to vial or syringe by the addition of a detergent. Injection at the proper depth produces a discrete pale elevation of the skin approximately 6-10mm in diameter. The test is usually read 48-72 after injection. An area of induration 10mm or more in diameter produced by the injection of 5 tuberculin units (TU) of PPD is considered a positive reaction. There are additional criteria when less than 10mm elevation are considered positive. THE TEST MUST BE PLACED AND INTERPRETED ONLY BY AN EXPERIENCED HEALTH PROFESSIONAL. NO EMPLOYEES OR STUDENTS MAY PLACE OR INTERPRET THEIR OWN PPD.

B. Screening at Time of Hiring & Beginning School

Two-step PPD required of all new employees and medical students.

All employees and students previously tuberculin negative should have a 5TU PPD (Mantoux) placed.

Consideration should be given to placing a second tuberculin test to see if there is a booster effect and to establish a valid baseline.

All individuals previously tuberculin positive should have a symptom check and history taken and be considered by a physician for a chest x-ray.

Those previously vaccinated with BCG should not be exempted from tuberculin testing. Those noted to be documented as positive may be exempted from testing but should then have a chest x-ray.

All individuals with positive tuberculin tests should be evaluated for prophylactic therapy and should be counseled regarding HIV testing.

Those individuals previously documented as PPD positive will be considered by a physician for a chest x-ray. They should be educated in signs and symptoms of TB and instructed to report their respective health service (Weiler, or Student Health), if any symptoms are noted. These employees and students should be followed with an annual (minimal) symptom check (cough, weight loss, fever, night sweats, hemoptysis). A chest x-ray should be performed as medically indicated if (new) symptoms are reported.

Those employees and students who are assigned to areas where the risk of exposure to tuberculosis is high, should have more frequent tuberculin screening/assessments. These areas include:

emergency room

pulmonary unit

methadone program

AIDS unit

inhalation therapy

infectious diseases unit

TB research laboratory

any other area where interval screening indicates a high rate of exposure

Those employees and students ascertained as new PPD converters should have an evaluation for active disease including a chest x-ray and counseling, and they should be offered prophylactic therapy as might be appropriate.

D.Assessment Following Exposure to an Undiagnosed Case of Tuberculosis

All employees and students previously tuberculin negative who have been assessed to be at risk following an inadvertent exposure to a patient (source) with active tuberculosis should have a tuberculin test within one week following the exposure.

Those ascertained as PPD negative should have a follow-up skin test in 12 weeks.

All new converters should have an evaluation for active disease including a chest x-ray and prophylactic treatment as might be medically appropriate.

Those employees and students who have a positive tuberculin test by history should have a symptom check at 12 weeks following exposure.

Employees/students exposed must be seen at Employee/Student Health Service for evaluation.

E. Special Concerns

Those individuals in immunosuppressive states who may be anergic, should have a tuberculin test placed with a concomitant anergy panel. If anergic, a chest x-ray should be performed as a baseline. The patient should be followed-up with a symptom check and chest x-ray when appropriate.

At risk employees and students will be counseled and receive training upon initial employment or enrollment and annually thereafter. The Department of Environmental Health and Safety will ensure that such training is provided by the appropriate health services or by the infection control, safety or training departments of the sites in which employees and students work. Employees and students shall be trained regarding the hazards and control of tuberculosis. At a minimum, the following subjects shall be discussed:

A. The cause and transmission of TB

B. Definition of "infectious"

C. The distinction between TB disease and TB infection

D. The purpose and interpretation of TB skin testing, including the significance of a skin test conversion

E. The signs and symptoms of TB

F. The reporting mechanism of the signs and symptoms

G. The purpose of preventive therapy

H. The risk factors for TB disease development

I. The treatment of TB and the origin and prognosis of multi-drug resistant TB

J. The purpose of surveillance and the recommended follow-up of positive skin tests

K. Site specific protocols

L. Association of HIV infection and tuberculosis

M. Exposure response.

Training for employees shall also include, if applicable:

N. The purpose, proper selection, fit, use and limitations of personal protective equipment

O. The engineering controls in use in the person's work area

P. The critical role directly observed therapy (DOT) plays in preventing the emergence of multiple drug resistant strains of TB.

The training shall be given to all students and to all at risk employees upon initial enrollment or employment and should be repeated annually thereafter.

XIII. What You Should Do If You Have Been Exposed to Tuberculosis?

If you have been exposed to the tubercle bacillus either from a patient or during the course of your laboratory research, you must be evaluated by your respective health service, either Weiler or Jacobi Hospitals. In addition, you may also visit your personal physician. The physician will determine the level of evaluation necessary to determine exposure, follow-up treatment, and required reporting.

XIV. Work Removal

When an employee or student is found to have current pulmonary or laryngeal TB, he/she shall be excluded from work until adequate treatment is instituted, his/her cough is resolved and the appropriate Health Service certifies that he/she is no longer infectious. Thereafter, he/she should be periodically assessed by the Health Service to ensure that he/she remains non-infectious.

This removal requirement does not include employees or students infected with TB at sites other than lung or larynx who are otherwise healthy and undergoing preventive therapy.

An employee who must be removed from the workplace because of TB should call the University Benefits Office (718) 430-3276 to determine what benefits, if any, may be applicable.

XV. Record Keeping and Reporting Regarding Exposure to Tuberculosis.

The employee's or student's medical record should contain his/her PPD skin test results and TB exposure history.

The record of all of the employee's or student's skin test results should include the date the test was performed and the size of the reaction.

An employee or student who has a positive PPD skin test should be questioned as to the possible source of exposure to TB and his/her job description and work history.

The employee's TB-related medical record should be kept at the Health Service for the term of employment plus thirty years.

All PPD skin test conversions that occur in active employees should be recorded on the OSHA 200 form and be reported to OSHA and, for employees working in licensed programs, to NYSDOH. Employees who are found to be PPD positive on preplacement testing should not be reported on the OSHA 200 form.

Employee and student TB-related medical information should be centrally maintained, to allow for identification of high-risk areas and procedures.

APPENDIX A

APPENDIX B

Summary of Einstein's Respiratory Protection Program

Prior to the issuance of a half-face respirator, all employees shall receive a medical exam to determine the employee's physical ability of wearing a respirator. For employees, Albert Einstein College of Medicine utilizes the services of an outside vendor for medical surveillance. Students are evaluated by our Occupational Health Service for respirator usage.

Prior to issuance of a TB-approved Respirator (N95), a medical questionnaire must be completed and approved by a physician or a licensed health care professional.

Upon the recommendation of the physician, the Albert Einstein College of Medicine's employees will be trained in the proper selection, use and maintenance of a respirator. The training program will include:

appropriate selection of a respirator for the specific hazard,

recognizing the limitations of a respirator,

understanding the operating principles and maintenance of a respirator, and

the importance of a properly fitted respirator.

The training will be conducted by the respirator manufacturer, the Environmental Health and Safety Department, or as otherwise designated by the institution in which the employee or student works.

All non-disposable respirators shall be cleaned after every use, regularly disinfected and stored in a convenient, clean, and sanitary location.

A detailed copy of Albert Einstein College of Medicine's RPP can be obtained from the Department of Environmental Health and Safety (X4150).

Bibliography

1. "An Outbreak of Tuberculosis in a Shelter for Homeless Men - A Description of Its Evolution and Control." from the Seattle-King County Department of Public Health and the University of Washington Schools of Medicine and Public Health and Community Medicine, Seattle, Washington, July 31, 1990.

13. Geiseler, P.J., Nelson, K.E., Crispen, R.G. and Moses, V.K. "Tuberculosis in Physicians: A Continuing Problem." Division of Infectious Diseases, Department of Medicine, Department of Preventative Medicine and the Institution for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, August 1985.

14. "Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Settings, with Special Focus on HIV-Related Issues." Morbidity and Mortality Weekly Report, December 7, 1991, Vol. 39, No.RR-17: U.S. Department of Health and Human Services, Public Health Service.

20. "Prevention and Control of Tuberculosis in Correctional Institutions: Recommendations of the Advisory Committee for the Elimination of Tuberculosis." Morbidity and Mortality Weekly Report, Vol. 38, No. 18, May 12, 1989.

21. "Prevention and Control of Tuberculosis in U.S. Communities with At-Risk Minority Populations and Prevention and Control of Tuberculosis Among Homeless Persons." Morbidity and Mortality Weekly Report, Vol. 41, No. RR-J, April 17, 1992.

25. "Screening for Tuberculosis and Tuberculosis Infection in High-Risk Populations and the Use of Preventative Therapy for Tuberculosis Infection in the U.S." Morbidity and Mortality Weekly Report, Vol. 39, No. RR-8, May 1990.